Frequent outbreaks of highly pathogenic avian influenza and the increasing data for comparative analysis require a central database specialized in influenza virus. The Influenza Virus Database (IVDB) is thus developed as an integrated information resource and analysis platform for genetic, genomic, and phylogenetic studies of influenza virus.

Influenza virus (IV) is the causative agent of several serious influenza pandemics. Recently, a highly pathogenic avian influenza virus (AIV; H5N1) has resulted in the death of more than 100 people and the slaughter of millions of poultry in Asia, Europe, and Africa. The Beijing Institute of Genomics (BIG), Chinese Academy of Sciences (CAS) has been sequencing various influenza viruses collected by scientists of different institutions from different parts of China. We have sequenced isolates of AIV subtype H5N1 from 1997 to 2005 in different hosts found in China, such as wild birds, poultry, water fowls, and mammals. Some of these strains have been published, such as those from tree sparrows in Henan Province in 2004 and migratory birds in Qinghai Province in 2005.

IVDB hosts complete genome sequences of influenza A virus generated by BIG and curates all other published influenza virus sequences after expert annotations. For the convenience of efficient data utilization, our Q-Filter system classifies and ranks all nucleotide sequences into 7 categories according to sequence content and integrity. IVDB provides a series of tools and viewers for analyzing the viral genomes, genes, genetic polymorphisms and phylogenetic relationships comparatively. A searching system is developed for users to retrieve a combination of different data types by setting various search options. To facilitate analysis of the global viral transmission and evolution, the IV Sequence Distribution Tool (IVDT) is developed to display worldwide geographic distribution of the viral genotypes and to couple genomic data with epidemiological data. The BLAST, multiple sequence alignment tools and phylogenetic analysis tools were integrated for online data analysis. Furthermore, IVDB offers instant access to the pre-computed alignments and polymorphism analysis of influenza virus genes and proteins and presents the results by SNP distribution plots and minor allele distributions. IVDB aims to be a powerful information resource and an analysis workbench for scientists working on IV genetics, evolution, diagnostics, vaccine development, and drug design.